1. Field of the Invention
This invention relates to an image display apparatus for displaying an image.
2. Description of the Prior Art
Heretofore, when displaying, for example, an image having an NTSC television signal using a television monitor apparatus conforming to a high-definition television system, the signal is supplied to the television monitor apparatus while increasing the number of scanning lines for the NTSC (National Television Systems Committee) television signal so as to conform to the high-definition television system. High definition television is generally recognized as a system which uses an increased number of horizontal lines of resolution per frame to enhance picture quality. Thus, as shown in FIG. 1, an image (reference numeral 21) of the NTSC television signal is displayed on a predetermined position on the picture surface (reference numeral 22) of the television monitor apparatus.
In the above-described conventional method, however, a blank portion on which an image is not displayed is present on the picture surface of the television monitor apparatus, as shown in FIG. 1, due to a difference in aspect ratio between the NTSC system and the high-definition television system. Such a blank portion is very uncomfortable to observe. In addition, the display picture surface of the television monitor apparratus cannot be effectively utilized.